Developing catalysts for the oxidation of water to dioxygen is important in understanding the molecular-level details of photosynthesis and also in designing alternative energy sources such as regenerative fuel cells. Owing to the thermodynamic and mechanistic constraints of the reaction and the additional requirement that the catalytic site be contained in a coordination environment that is stable under oxidizing conditions, it is perhaps not surprising that there are relatively few well-characterized water oxidation catalysts.
The majority of non-biological water oxidation catalysts are related to the μ-oxy bonded di-ruthenium system first studied by Meyer et al. Gersten, S. W.; Samuels, G. J.; Meyer, T. J., J. Am. Chem. Soc. 1982, 104, 4029. Other synthetic water oxidation catalysts are known and have been reviewed by Dismukes et al. Rüttinger, W.; Dismukes, G. C. Chem. Rev. 1997, 97, 1.
Water oxidation can be carried out, for example, photocatalytically and electrocatalytically. The study of electrocatalytic water oxidation has focused on metal oxide systems, including RuO2 and IrO2.
A need still exists for water oxidation catalysts.